The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Juan Carlos Izpisua Belmonte - One of the best experts on this subject based on the ideXlab platform.
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retinoic acid signalling links left right asymmetric patterning and biLaterally symmetric somitogenesis in the zebrafish embryo
Nature, 2005Co-Authors: Yasuhiko Kawakami, Angel Raya, Marina R Raya, Concepcion Rodriguezesteban, Juan Carlos Izpisua BelmonteAbstract:During embryogenesis, cells are spatially patterned as a result of highly coordinated and stereotyped morphogenetic events. In the vertebrate embryo, information on Laterality is conveyed to the node, and subsequently to the Lateral Plate Mesoderm, by a complex cascade of epigenetic and genetic events, eventually leading to a left-right asymmetric body plan. At the same time, the paraxial Mesoderm is patterned along the anterior-posterior axis in metameric units, or somites, in a biLaterally symmetric fashion. Here we characterize a cascade of Laterality information in the zebrafish embryo and show that blocking the early steps of this cascade (before it reaches the Lateral Plate Mesoderm) results in random left-right asymmetric somitogenesis. We also uncover a mechanism mediated by retinoic acid signalling that is crucial in buffering the influence of the flow of Laterality information on the left-right progression of somite formation, and thus in ensuring biLaterally symmetric somitogenesis.
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notch activity acts as a sensor for extracellular calcium during vertebrate left right determination
Nature, 2004Co-Authors: Angel Raya, Yasuhiko Kawakami, Concepcion Rodriguezesteban, Marta Ibanes, Diego Rasskingutman, Joaquin Rodriguezleon, Dirk Buscher, Jose A Feijo, Juan Carlos Izpisua BelmonteAbstract:During vertebrate embryo development, the breaking of the initial biLateral symmetry is translated into asymmetric gene expression around the node and/or in the Lateral Plate Mesoderm. The earliest conserved feature of this asymmetric gene expression cascade is the left-sided expression of Nodal, which depends on the activity of the Notch signalling pathway. Here we present a mathematical model describing the dynamics of the Notch signalling pathway during chick embryo gastrulation, which reveals a complex and highly robust genetic network that locally activates Notch on the left side of Hensen's node. We identify the source of the asymmetric activation of Notch as a transient accumulation of extracellular calcium, which in turn depends on left-right differences in H+/K+-ATPase activity. Our results uncover a mechanism by which the Notch signalling pathway translates asymmetry in epigenetic factors into asymmetric gene expression around the node.
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wnt signals control fgf dependent limb initiation and aer induction in the chick embryo
Cell, 2001Co-Authors: Yasuhiko Kawakami, Dirk Buscher, Javier Capdevila, Tohru Itoh, Concepcion Rodriguez Esteban, Juan Carlos Izpisua BelmonteAbstract:Abstract A regulatory loop between the fibroblast growth factors FGF-8 and FGF-10 plays a key role in limb initiation and AER induction in vertebrate embryos. Here, we show that three WNT factors signaling through β-catenin act as key regulators of the FGF-8/FGF-10 loop. The Wnt-2b gene is expressed in the intermediate Mesoderm and the Lateral Plate Mesoderm in the presumptive chick forelimb region. Cells expressing Wnt-2b are able to induce Fgf-10 and generate an extra limb when implanted into the flank. In the presumptive hindlimb region, another Wnt gene, Wnt-8c , controls Fgf-10 expression, and is also capable of inducing ectopic limb formation in the flank. Finally, we also show that the induction of Fgf-8 in the limb ectoderm by FGF-10 is mediated by the induction of Wnt-3a. Thus, three WNT signals mediated by β-catenin control both limb initiation and AER induction in the vertebrate embryo.
Ruijin Huang - One of the best experts on this subject based on the ideXlab platform.
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The Lateral Plate Mesoderm: a novel source of skeletal muscle.
Results and problems in cell differentiation, 2014Co-Authors: Ketan Patel, Ruijin HuangAbstract:It has been established in the last century that the skeletal muscle cells of vertebrates originate from the paraxial Mesoderm. However, recently the Lateral Plate Mesoderm has been identified as a novel source of the skeletal muscle. The branchiomeric muscles, such as masticatory and facial muscles, receive muscle progenitor cells from both the cranial paraxial Mesoderm and Lateral Plate Mesoderm. At the occipital level, the Lateral Plate Mesoderm is the sole source of the muscle progenitors of the dorsoLateral neck muscle, such as trapezius and sternocleidomastoideus in mammals and cucullaris in birds. The Lateral Plate Mesoderm requires a longer time for generating skeletal muscle cells than the somites. The myogenesis of the Lateral Plate is determined early, but not cell autonomously and requires local signals. Lateral Plate myogenesis is regulated by mechanisms controlling the cranial myogenesis. The connective tissue of the Lateral Plate-derived muscle is formed by the cranial neural crest. Although the cranial neural crest cells do not control the early myogenesis, they regulate the patterning of the branchiomeric muscles and the cucullaris muscle. Although satellite cells derived from the cranial Lateral Plate show distinct properties from those of the trunk, they can respond to local signals and generate myofibers for injured muscles in the limbs. In this review, we key feature in detail the muscle forming properties of the Lateral Plate Mesoderm and propose models of how the myogenic fate may have arisen.
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The occipital Lateral Plate Mesoderm is a novel source for vertebrate neck musculature
Development (Cambridge England), 2010Co-Authors: Susanne Theis, Anthony Otto, Petr Valasek, Eldad Tzahor, Itamar Harel, Shahragim Tajbakhsh, Ketan Patel, Bodo Christ, Ruijin HuangAbstract:In vertebrates, body musculature originates from somites, whereas head muscles originate from the cranial Mesoderm. Neck muscles are located in the transition between these regions. We show that the chick occipital Lateral Plate Mesoderm has myogenic capacity and gives rise to large muscles located in the neck and thorax. We present molecular and genetic evidence to show that these muscles not only have a unique origin, but additionally display a distinct temporal development, forming later than any other muscle group described to date. We further report that these muscles, found in the body of the animal, develop like head musculature rather than deploying the programme used by the trunk muscles. Using mouse genetics we reveal that these muscles are formed in trunk muscle mutants but are absent in head muscle mutants. In concordance with this conclusion, their connective tissue is neural crest in origin. Finally, we provide evidence that the mechanism by which these neck muscles develop is conserved in vertebrates.
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somitic origin of the medial border of the mammalian scapula and its homology to the avian scapula blade
Journal of Anatomy, 2010Co-Authors: Petr Valasek, Milos Grim, Susanne Theis, Eliska Krejci, Flavio Maina, Yulia Shwartz, Anthony Otto, Ruijin HuangAbstract:The scapula is the main skeletal element of the pectoral girdle allowing muscular fixation of the forelimb to the axial skeleton. The vertebrate limb skeleton has traditionally been considered to develop from the Lateral Plate Mesoderm, whereas the musculature originates from the axial somites. However, in birds, the scapular blade has been shown to develop from the somites. We investigated whether a somitic contribution was also present in the mammalian scapula. Using genetic lineage-tracing techniques, we show that the medial border of the mammalian scapula develops from somitic cells. The medial scapula border serves as the attachment site of girdle muscles (serratus anterior, rhomboidei and levator scapulae). We show that the development of these muscles is independent of the mechanism that controls the formation of all other limb muscles. We suggest that these muscles be specifically referred to as medial girdle muscles. Our results establish the avian scapular blade and medial border of the mammalian scapula as homologous structures as they share the same developmental origin.
Ketan Patel - One of the best experts on this subject based on the ideXlab platform.
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The Lateral Plate Mesoderm: a novel source of skeletal muscle.
Results and problems in cell differentiation, 2014Co-Authors: Ketan Patel, Ruijin HuangAbstract:It has been established in the last century that the skeletal muscle cells of vertebrates originate from the paraxial Mesoderm. However, recently the Lateral Plate Mesoderm has been identified as a novel source of the skeletal muscle. The branchiomeric muscles, such as masticatory and facial muscles, receive muscle progenitor cells from both the cranial paraxial Mesoderm and Lateral Plate Mesoderm. At the occipital level, the Lateral Plate Mesoderm is the sole source of the muscle progenitors of the dorsoLateral neck muscle, such as trapezius and sternocleidomastoideus in mammals and cucullaris in birds. The Lateral Plate Mesoderm requires a longer time for generating skeletal muscle cells than the somites. The myogenesis of the Lateral Plate is determined early, but not cell autonomously and requires local signals. Lateral Plate myogenesis is regulated by mechanisms controlling the cranial myogenesis. The connective tissue of the Lateral Plate-derived muscle is formed by the cranial neural crest. Although the cranial neural crest cells do not control the early myogenesis, they regulate the patterning of the branchiomeric muscles and the cucullaris muscle. Although satellite cells derived from the cranial Lateral Plate show distinct properties from those of the trunk, they can respond to local signals and generate myofibers for injured muscles in the limbs. In this review, we key feature in detail the muscle forming properties of the Lateral Plate Mesoderm and propose models of how the myogenic fate may have arisen.
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The occipital Lateral Plate Mesoderm is a novel source for vertebrate neck musculature
Development (Cambridge England), 2010Co-Authors: Susanne Theis, Anthony Otto, Petr Valasek, Eldad Tzahor, Itamar Harel, Shahragim Tajbakhsh, Ketan Patel, Bodo Christ, Ruijin HuangAbstract:In vertebrates, body musculature originates from somites, whereas head muscles originate from the cranial Mesoderm. Neck muscles are located in the transition between these regions. We show that the chick occipital Lateral Plate Mesoderm has myogenic capacity and gives rise to large muscles located in the neck and thorax. We present molecular and genetic evidence to show that these muscles not only have a unique origin, but additionally display a distinct temporal development, forming later than any other muscle group described to date. We further report that these muscles, found in the body of the animal, develop like head musculature rather than deploying the programme used by the trunk muscles. Using mouse genetics we reveal that these muscles are formed in trunk muscle mutants but are absent in head muscle mutants. In concordance with this conclusion, their connective tissue is neural crest in origin. Finally, we provide evidence that the mechanism by which these neck muscles develop is conserved in vertebrates.
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regulation of epha4 expression in paraxial and Lateral Plate Mesoderm by ectoderm derived signals
Developmental Dynamics, 2001Co-Authors: Corina Schmidt, Bodo Christ, Malcolm Maden, Beate Brandsaberi, Ketan PatelAbstract:Somitogenesis in all vertebrates involves a mesenchymal to epithelial transition of segmental Plate cells. Such a transition involves cells altering their morphology and their adhesive properties. The Eph family of receptor tyrosine kinases has been postulated to regulate cytoskeletal organization. In this study, we show that a receptor belonging to this family, EphA4, is expressed in the segmental Plate in a region where cells are undergoing changes in cell shape as a prelude to epithelialization. We have identified the ectoderm covering the somites and the midline ectoderm as sources of signals capable of inducing EphA4. Loss of EphA4 results in cells of irregular morphology and somites fail to form. We also show that when somites fail to develop, expression of EphA4 in the Lateral Plate is also lost. We suggest that signaling occurs between the somites and the Lateral Plate Mesoderm and provide evidence that retinoic acid is involved in this communication. © 2001 Wiley-Liss, Inc.
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experimental induction ofbmp 4expression leads to apoptosis in the paraxial and Lateral Plate Mesoderm
Developmental Biology, 1998Co-Authors: Corina Schmidt, Ketan Patel, Bodo Christ, Beate BrandsaberiAbstract:Abstract In the avian embryo, epithelialization of the segmental Plate and formation of an epithelial dermomyotome depend on signals from the neural tube and the ectoderm overlying the paraxial Mesoderm. In this study, we report that ectoderm removal in combination with barrier insertion between the axial organs and the segmental Plate leads to an induction of BMP-4 expression in the paraxial Mesoderm. In the Lateral Plate, ectoderm removal alone leads to an increase of BMP-4 expression. Application of BMP-4 protein results in a lack of epithelialization of the paraxial Mesoderm. In order to investigate whether the loss of epithelial structures after these manipulations can be attributed to a change in cell fate, a change in cell proliferation, or the induction of apoptosis, the paraxial Mesoderm was tested for expression of Msx-2, BMP-2, BMP-4, and BMP-7. Moreover, BrdU and TUNEL staining were carried out. The inhibition of epithelialization after ectoderm removal alone and after segregation of the axial organs is accompanied neither by an increase in apoptosis nor by a reduction of the proliferation rate in the paraxial Mesoderm. On the other hand, an ectopic BMP-4 expression in the paraxial Mesoderm after ectoderm removal in combination with barrier insertion coincides with the occurrence of apoptotic cells and reduction of proliferation rate in this tissue. Increase of apoptosis and decrease in cell proliferation are observed in the paraxial and Lateral Plate Mesoderm also after application of BMP-4 protein.
Susanne Theis - One of the best experts on this subject based on the ideXlab platform.
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The occipital Lateral Plate Mesoderm is a novel source for vertebrate neck musculature
Development (Cambridge England), 2010Co-Authors: Susanne Theis, Anthony Otto, Petr Valasek, Eldad Tzahor, Itamar Harel, Shahragim Tajbakhsh, Ketan Patel, Bodo Christ, Ruijin HuangAbstract:In vertebrates, body musculature originates from somites, whereas head muscles originate from the cranial Mesoderm. Neck muscles are located in the transition between these regions. We show that the chick occipital Lateral Plate Mesoderm has myogenic capacity and gives rise to large muscles located in the neck and thorax. We present molecular and genetic evidence to show that these muscles not only have a unique origin, but additionally display a distinct temporal development, forming later than any other muscle group described to date. We further report that these muscles, found in the body of the animal, develop like head musculature rather than deploying the programme used by the trunk muscles. Using mouse genetics we reveal that these muscles are formed in trunk muscle mutants but are absent in head muscle mutants. In concordance with this conclusion, their connective tissue is neural crest in origin. Finally, we provide evidence that the mechanism by which these neck muscles develop is conserved in vertebrates.
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somitic origin of the medial border of the mammalian scapula and its homology to the avian scapula blade
Journal of Anatomy, 2010Co-Authors: Petr Valasek, Milos Grim, Susanne Theis, Eliska Krejci, Flavio Maina, Yulia Shwartz, Anthony Otto, Ruijin HuangAbstract:The scapula is the main skeletal element of the pectoral girdle allowing muscular fixation of the forelimb to the axial skeleton. The vertebrate limb skeleton has traditionally been considered to develop from the Lateral Plate Mesoderm, whereas the musculature originates from the axial somites. However, in birds, the scapular blade has been shown to develop from the somites. We investigated whether a somitic contribution was also present in the mammalian scapula. Using genetic lineage-tracing techniques, we show that the medial border of the mammalian scapula develops from somitic cells. The medial scapula border serves as the attachment site of girdle muscles (serratus anterior, rhomboidei and levator scapulae). We show that the development of these muscles is independent of the mechanism that controls the formation of all other limb muscles. We suggest that these muscles be specifically referred to as medial girdle muscles. Our results establish the avian scapular blade and medial border of the mammalian scapula as homologous structures as they share the same developmental origin.
Joshua S Waxman - One of the best experts on this subject based on the ideXlab platform.
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retinoic acid signaling restricts the size of the first heart field within the anterior Lateral Plate Mesoderm
Developmental Biology, 2021Co-Authors: Tiffany B Duong, Joshua S Waxman, Andrew HolowieckiAbstract:Retinoic acid (RA) signaling is required to restrict heart size through limiting the posterior boundary of the vertebrate cardiac progenitor field within the anterior Lateral Plate Mesoderm (ALPM). However, we still do not fully understand how different cardiac progenitor populations that contribute to the developing heart, including earlier-differentiating first heart field (FHF), later-differentiating second heart field (SHF), and neural crest-derived progenitors, are each affected in RA-deficient embryos. Here, we quantified the number of cardiac progenitors and differentiating cardiomyocytes (CMs) in RA-deficient zebrafish embryos. While Nkx2.5+ cells were increased overall in the nascent hearts of RA-deficient embryos, unexpectedly, we found that the major effect within this population was a significant expansion in the number of differentiating FHF CMs. In contrast to the expansion of the FHF, there was a progressive decrease in SHF progenitors at the arterial pole as the heart tube elongated. Temporal differentiation assays and immunostaining in RA-deficient embryos showed that the outflow tracts (OFTs) of the hearts were significantly smaller, containing fewer differentiated SHF-derived ventricular CMs and a complete absence of SHF-derived smooth muscle at later stages. At the venous pole of the heart, pacemaker cells of the sinoatrial node also failed to differentiate in RA-deficient embryos. Interestingly, genetic lineage tracing showed that the number of neural-crest derived CMs was not altered within the enlarged hearts of RA-deficient zebrafish embryos. Altogether, our data show that the enlarged hearts in RA-deficient zebrafish embryos are comprised of an expansion in earlier differentiating FHF-derived CMs coupled with a progressive depletion of the SHF, suggesting RA signaling determines the relative ratios of earlier- and later-differentiation cardiac progenitors within an expanded cardiac progenitor pool.
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cyp26 enzymes are required to balance the cardiac and vascular lineages within the anterior Lateral Plate Mesoderm
Development, 2014Co-Authors: Ariel B Rydeen, Joshua S WaxmanAbstract:Normal heart development requires appropriate levels of retinoic acid (RA) signaling. RA levels in embryos are dampened by Cyp26 enzymes, which metabolize RA into easily degraded derivatives. Loss of Cyp26 function in humans is associated with numerous developmental syndromes that include cardiovascular defects. Although previous studies have shown that Cyp26-deficient vertebrate models also have cardiovascular defects, the mechanisms underlying these defects are not understood. Here, we found that in zebrafish, two Cyp26 enzymes, Cyp26a1 and Cyp26c1, are expressed in the anterior Lateral Plate Mesoderm (ALPM) and predominantly overlap with vascular progenitors (VPs). Although singular knockdown of Cyp26a1 or Cyp26c1 does not overtly affect cardiovascular development, double Cyp26a1 and Cyp26c1 (referred to here as Cyp26)-deficient embryos have increased atrial cells and reduced cranial vasculature cells. Examining the ALPM using lineage tracing indicated that in Cyp26-deficient embryos the myocardial progenitor field contains excess atrial progenitors and is shifted anteriorly into a region that normally solely gives rise to VPs. Although Cyp26 expression partially overlaps with VPs in the ALPM, we found that Cyp26 enzymes largely act cell non-autonomously to promote appropriate cardiovascular development. Our results suggest that localized expression of Cyp26 enzymes cell non-autonomously defines the boundaries between the cardiac and VP fields within the ALPM through regulating RA levels, which ensures a proper balance of myocardial and endothelial lineages. Our study provides novel insight into the earliest consequences of Cyp26 deficiency that underlie cardiovascular malformations in vertebrate embryos.
